Within recent years, telephone sets incorporating push-button arrays, commonly including twelve such push-buttons, have come into widespread use and have largely supplanted the previously common rotary dial-type telephone. The individual push-buttons comprising such a telephone set array normally project through the cover of the telephone, or a portion of the telephone cover. The remainder of the switching array is contained beneath this outer shell of the telephone set. In various environments, including especially industrial and commercial environments, but as well in the home, this telephone set which is usually conveniently placed with respect to a work station, is subject to damage from environmental hazards, including especially to spillage of liquids which can readily seep through the openings surrounding the individual push button keys and cause damage, in some cases irreparable damage, to the underlying switching device.
While several types of covering elements have been previously proposed for use in connection with push button-type telephones, these have not addressed the foregoing problem of providing a protective envelopment of the push button array to prevent damage, especially from liquids. For example, patents such as U.S. Pat. Nos. 3,739,105; 3,927,282; 4,002,855; and 3,345,769, have been concerned with a variety of problems including arrangements for facilitating dialing by varying spacing of the actuating means for the individual push-buttons, or in the case of U.S. Pat. No. 3,345,769, providing a means for supporting message pads or the like.
Of particular interest in connection with the present invention is the teaching in the aforementioned U.S. Pat. No. 3,739,105, that the push buttons on the covering device can be formed to provide a width of material which glows in the dark, thereby facilitating use of the telephone in darkened surroundings.
The problem of providing an adaptation enabling use of a push button telephone under darkened conditions, is indeed a problem which has been occasionally addressed, but never adequately met. Thus, it may be noted that numerous prior art devices extending back many years and directed toward a similar problem in a rotary dial telephone, have considered use of phosphorescent materials in some manner as to enable limited visible under darkened conditions as in the mentioned U.S. Pat. No. 3,739,105.
Pursuant to the foregoing, it may be regarded as an object of the present invention to provide a simple, inexpensive to manufacture cover for use with a push button dial telephone or the like, which device acts to effectively seal the push button array against damage by liquids or other hazards, while at the same time providing no interference with use in actuation of the push buttons.
It is a further object of the present invention to provide a protective cover of the above character which may further include phosphorescent indicia to enable visibility under reduced light conditions.